1. FIELD OF THE INVENTION
The present invention relates to a sensor for measuring the elongation of a structural member in a bore.
2. DESCRIPTION OF THE PRIOR ART
The German specification DE-A-25 37 369 discloses elongation meters having a measuring rod mounted to an end of a bore of which the free end cooperates with a measuring device which detects the difference of length between the structural member having a bore and the measuring rod upon a loading of the structural member. The measuring device is designed as device for detecting a tube-bending force and includes at the area of the largest deflection at least one resistive wire strain or wire strain gauge, respectively.
Such measuring detectors have the drawback that due to the thread and the different linear extensions the conversion of measuring signals is inaccurate.